Applications of soft-switching full-bridge converter and rotational electric field to transdermal drug delivery

This paper presents applications of a soft-switching full-bridge converter to generate pulsed voltage (PV) for exciting tissue, which includes transdermal drug delivery (TDD), transcutaneous electrical nerve stimulation, functional electrical stimulation, etc. Particularly, in TDD it offers many potential advantages over conventional methods, such as oral and injection, and it avoids drug degradation through gastro-intestinal and liver. To design a portable driving system with battery source, the proposed converter is equipped with a soft-switching cell to achieve zero voltage switching or zero current switching, improving efficiency about 20%. The overall system needs only a set of soft-switching cell to achieve soft-switching feature even though there are N sets of PVs, reducing size and cost significantly. Moreover, a rotational electrical field concept is introduced to further improve effectiveness of drug delivery. Experimental results of a 150 V output voltage and 18 W peak power have demonstrated the feasibility of the proposed converter.